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New York City’s first-in-the-nation trans fat ban has paid off, at least in the short term. A study comparing meals at fast food chains before and after the 2006 ban shows a drop in consumption of the heart-damaging trans fat.

While trans fat occurs naturally in some foods, like dairy products and meat, Americans mainly consume it as a processed form of fat, like the partially hydrogenated oils found in baked goods and sometimes used to cook French fries.

In the study, published in the Annals of Internal Medicine, researchers from the New York City Department of Health and Mental Hygiene looked at meals eaten at 168 randomly selected city locations of 11 fast food chains, including McDonald’s, KFC, Pizza Hut and others.

By 2009, consumption of trans fats at fast food chains in New York City had dropped by an average of 2.4 grams per meal, down to about half a gram. The largest decrease was seen in hamburger chains, followed by Mexican and fried chicken restaurants.

In addition, the number of meals that contained zero grams of trans fat increased from 32 percent before the ban to 59 percent after.

The researchers did not follow the diners long enough to see if there are long-term health benefits from the ban, such as reduced risk of heart disease or obesity. Other studies, though, have shown that eating 40 calories a day of trans fat can increase your risk of heart disease by up to 23 percent.

Cutting back on trans fat in your diet, then, is likely to have a positive impact on your health—even if it’s the city that’s pushing you to eat better.